Golden Logarithmic Spiral, also known as equiangular spiral, and Spira Mirabilis.
For growth factor b = 0.306349 (approx.), the Golden Spiral is formed, for angles in radians.
a is a scale factor.
c is the number of "coils."
_FxGraph3D a*cos(c*v)*exp(b*c*v);a*sin(c*v)*exp(b*c*v);0;0;1;0;6.283185307179586;0;50;1;0.306349;2;UV

- Brian